The soil is an important part of the landscape and contributes to determine the way in which natural vegetation, crops and human settlements are distributed on the territory. But the importance of the soil is mainly related to its double role as a reserve of nutritional elements and water and mechanical support (how would plants be able to stand upright if they did not have the soil to put their roots in?) for vegetation, leading to the creation of forests and protected areas. A direct observation allows us to see the fundamental importance of the soil: if we go to the mountains or to the countryside, we will see some bare rocks without plants, but next to them there will be wider areas covered by a thick soil. On this land spontaneous vegetation or crops grow. The soil is also very important for men and other living organisms as it affects water composition. In fact, the quality of underground water reserves depends on use of organic and inorganic polluting products, deriving from agricultural and industrial activities or from cities. Various chemical and physical properties of the soil affect the concentration and permanence of polluting compounds in the soil, and the probability that they get in contact with superficial aquifers by polluting them. The soil can be extremely important for men even if it is not changed and left in its natural conditions. This is the case of protected areas (parks and oasis): the survival of the delicate ecosystems of these areas mainly depends on the fact that the soil keeps in good conditions and does not experience changes. For example, in the past men considered wet areas as unhealthy areas to be reclaimed and used for agriculture. Today wet areas are considered as very important and fragile ecosystems, whose survival can be guaranteed only by preserving the particular conditions of their soil. Soil is one of the most important and essential natural resources. Farmers and gardeners know this fact and go to great efforts to…